Fiberglass reinforced textile bobbin



- Oct. 31, 1967 A. J. GREEN FIBERGLASS REINFORCED TEXTILE BOBBIN Filed 001;. '20, 1965 g4 IVENTOR 149 7661 J Green United States Patent 3,350,030 FIBERGLASS REINFORCED TEXTILE BOBBIN Alfred J. Green, Yorklyn, Del., assignor to NVF Company, a corporation of Delaware Filed Oct. 20, 1965, Ser. No, 498,375 2 Claims. (Cl. 242-118.32)

ABSTRACT OF THE DISCLOSURE The textile bobbin includes a tubular core of resinilnpregnated fibrous material having a strengthening layer of fiberglass strands concentrically sandwiched between inner and outer layers of fibrous material. The fiberglass layer includes strands wound at a high helix angle at about 50 to 70 sandwiched between strands wound at a low helix angle at about 1 to 20 with a major portion of the fiberglass strand being at the low helix angle.

This invention relates to textile bobbins and their manufacture and more particularly to such bobbins which are used as tensioning spools for nylon thread and the like.

Textile thread such as nylon and the like are for some uses such as tire cording and the like wound during processing on bobbins to stretch the thread and maintain it under tension. This is done for example by rotating the bobbin at a faster rate than the thread is fed to it. Wrapping the thread at the desired tension or prestretching however creates a dilema with conventional bobbins. For example, if on the one hand, the thread is wrapped under the desired extremely high tension, the bobbin will crack or otherwise fail. On the other hand, if the thread is not wrapped so tight, the proper amount of tension or prestretching is not attained.

An object of this invention is to provide an effective, non-metallic bobbin which can withstand the tremendous force applied by tightly wrapping textile thread, such as nylon, thereon for tensioning purposes.

A further object is to provide an economical and reliable method of manufacturing such bobbins.

In accordance with this invention, the resin-impregnated core of the bobbin is made of relatively inexpensive compressed fibrous material such as paper with fiberglass reinforcing strands wrapped or reaved thereon. It has been found that when the fiberglass strands are wrapped at a relatively low helix angle, the resultant bobbin is made resistant to longitudinal cracking caused by lateral inward forces. The bobbin, however, even with superior hoop strength would still tend to crack laterally. It has also been found, however, that bobbins can be made resistant to this lateral cracking by wrapping the fiberglass strands at a relatively high helix angle to thus impart longitudinal strength to the bobbin. The bobbins of this invention are thus made by wrapping or reaving the fiberglass strands at both high and low helix angles until the core is sufficiently covered. Advantageously, these high and low angles may vary, but experience indicates that between 50 and 70 and between 1 and 20, respectively, and preferably approximately 60 and respectively, provide superior results.

Novel features and advantages of the present invention will become apparent to one skilled in the art from a reading of the following description in conjunction with the accompanying drawings wherein similar reference characters refer to similar parts and in which:

FIG. 1 is an end view of a bobbin in accordance with one embodiment of this invention;

FIG. 2 is a cross-sectional view taken through FIG. 1 along the line 22; and

FIGS. 3-5 are side views in elevation of a bobbin during different phases of manufacture.

Patented Oct. 31, 1967 "ice As most clearly shown in FIG. 2, the bobbin 10 accordmg to the preferred embodiment of this invention includes a cylindrical compressed resin-impregnated fibrous core 12 made for example of phenolic paper. The core 12 has for example a layer 14 of epoxy resin coated fiberglass filaments thereon. The fiberglass layer 14 in turn has another layer of resin-impregnated phenolic paper thereon, upon which the nylon or other material is wound for tensioning during use.

A supporting ring 18 may be pressed into each end of the bobbin 10 to support the bobbin on the centering collet of the textile tensioning machine.

Fiberglass layer 14 is formed by reaving fiberglass strands around core 12. As indicated in FIG. 3 strands 20 are disposed at a relatively low helix angle of between about 1 and 44, and preferably between about 1 and 20, with the most advantageous angle being 10. The strands 20' are helically applied back and forth across the entire length of the core 12. A second set of fiberglass strands 22 is then reaved back and forth across the entire length of the core 12 at a relatively high helix angle of between about 46 and 89, and preferably between about 50 and 70, with the most advantageous being 60. The reaving of the fiberglass strands at these angles is continued until the desired thickness is obtained. As indicated in FIG. 5 the resultant assembly includes a number of partially completed bobbins 24 comprising fiberglass strands coating core 12. Outer sleeve 16 is then applied to this assembly and the assembly is cut to the required sizes. Rings 18 are then secured in place to form the completed bobbins.

The fiberglass strands may be applied at a much higher feed rate and thus more economically, and with a greater packing effect, at a low helix angle, than at a high helix angle. Accordingly, it is very desirable to initially apply the fiberglass at a low helix angle directly on the core 12 until about one-third of the desired fiberglass layer has been built up. The high helix angle strands are then ap plied, until about another one third of the fiberglass layer has been built up. A final application of the fiberglass strands at the low helix angle builds up the remaining one-third of the core. This arrangement is particularly advantageous because the high helix angle strands are sandwiched between layers of very tightly packed low helix strands. Additionally, if as is useful in some operations, the strands are later ground or otherwise machined to attain a higher degree of smoothness before applying the outer fiber layer, it is a portion of the less expensively applied low helix strands which are sacrificed. Further, the low helix strands comprise from about to of all the fiberglass strands without adversely affecting the resistance to lateral cracking.

The bobbins 10 are made by first winding the resin coated fibrous material such as phenolic paper in sheet form around a central mandrel to form an inner layer or core 12. The desired fiberglass layer 14 is then applied, as noted above. In certain operations, it may be desirable to machine the outer surface of the fiberglass layer at this stage to improve this surface for the next operation. The outer resin coated fibrous material 16, such as phenolic paper, is next applied in sheet form, and external mechanical pressure and heat are utilized, such as a line chanical hot press, to cure the resin impregnating the materials. Finally, the mandrel is withdrawn and the ends of the tubular laminated member (comprising layers 12, 14 and 16) are machined to form the finished textile bobbin.

Obviously, many modifications and variations of the present invention are possible in the light of the above teachings.

It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. A textile bobbin comprising a generally tubular core of compressed, resin-impregnated fibrous material including a strengthening layer of fiberglass strands, a portion of the fiberglass strands being helically arranged to impart lateral strength and another portion of the fiberglass strands being helically arranged to impart longitudinal strength to the bobbin, said fiberglass strands arranged to impart lateral strength being positioned at a relatively low helix angle of about 1 to 20, said fiberglass strands arranged to impart longitudinal strength being positioned at a relatively high helix angle of about 50 to 70, said layer of fiberglass strands being concentrically sandwiched between inner and outer layers of fibrous material, a major portion of said fiberglass strands being positioned at said low helix angle, said high helix angle strands being sandwiched between low helix angle strands, and textile thread under tension being wound on said core.

2. A textile bobbin as in claim 1 wherein said core is essentially cylindrical, and approximately from /3 to of said fiberglass strands being positioned at a relatively low helix angle of approximately 10, and approximately from A to /3 of said fiberglass strands being positioned at a relatively high helix angle of approximately 60.

References Cited UNITED STATES PATENTS 1,312,780 8/1919 Fenn 138-144 2,847,786 8/1958 Hartley et al. 2,854,031 9/1958 Donaldson 138141 X 3,105,786 10/1963 Anderson 156-l73 3,152,804 10/1964 Costopoulos 156-172 X FRANK I. COHEN, Primary Examiner.

GEORGE F. MAUTZ, Examiner. 

1. A TEXTILE BOBBIN COMPRISING A GENERALLY TUBULAR CORE OF COMPRESSED, RESIN-IMPREGNATED FIBROUS MATERIAL INCLUDING A STRENGTHENING LAYER OF FIBERGLASS STRANDS, A PORTION OF THE FIBERGLASS STRANDS BEING HELICALLY ARRANGED TO IMPART LATERAL STRENGTH AND ANOTHER PORTION OF THE FIBERGLASS STRANDS BEING HELICALLY ARRANGED TO IMPART LONGITUDINAL STRENGTH TO THE BOBBION, SAID FIBERGLASS STRANDS ARRANGED TO IMPART LATERAL STRENGTH BEING POSITIONED AT A RELATIVELY LOW HELIX ANGLE OF ABOUT 1* TO 20*, SAID FIBERGLASS STRANDS ARRANGED TO IMPART LONGITUDINAL STRENGTH BEING POSITIONED AT A RELATIVELY HIGH HELIX ANGLE OF ABOUT 50* TO 70*, SAID LAYER OF FIBERGLASS STRANDS BEING CONCENTRICALLY SANDWICHED BETWEEN INNER AND OUTER LAYERS OF FIBROUS MATERIAL, A MAJOR PORTION OF SAID FIBERGLASS STRANDS BEING POSITIONED AT SAID LOW HELIX ANGLE, SAID HIGH HELIX ANGLE STRANDS BEING SANDWICHED BETWEEN LOW HELIX ANGLE STRANDS, AND TEXTILE THREAD UNDER TENSION WOUND ON SAID CORE. 